/* eslint-disable */
/****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Copyright (C) 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com>
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWebChannel module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
 ** General Public License version 3 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL3 included in the
 ** packaging of this file. Please review the following information to
 ** ensure the GNU Lesser General Public License version 3 requirements
 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 2.0 or (at your option) the GNU General
 ** Public license version 3 or any later version approved by the KDE Free
 ** Qt Foundation. The licenses are as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
 ** included in the packaging of this file. Please review the following
 ** information to ensure the GNU General Public License requirements will
 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and
 ** https://www.gnu.org/licenses/gpl-3.0.html.
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

'use strict'

var QWebChannelMessageTypes = {
    signal: 1,
    propertyUpdate: 2,
    init: 3,
    idle: 4,
    debug: 5,
    invokeMethod: 6,
    connectToSignal: 7,
    disconnectFromSignal: 8,
    setProperty: 9,
    response: 10
}

var QWebChannel = function(transport, initCallback) {
    if (typeof transport !== 'object' || typeof transport.send !== 'function') {
        console.error(
            'The QWebChannel expects a transport object with a send function and onmessage callback property.' +
                ' Given is: transport: ' +
                typeof transport +
                ', transport.send: ' +
                typeof transport.send
        )
        return
    }

    var channel = this
    this.transport = transport

    this.send = function(data) {
        if (typeof data !== 'string') {
            data = JSON.stringify(data)
        }
        channel.transport.send(data)
    }

    this.transport.onmessage = function(message) {
        var data = message.data
        if (typeof data === 'string') {
            data = JSON.parse(data)
        }
        switch (data.type) {
            case QWebChannelMessageTypes.signal:
                channel.handleSignal(data)
                break
            case QWebChannelMessageTypes.response:
                channel.handleResponse(data)
                break
            case QWebChannelMessageTypes.propertyUpdate:
                channel.handlePropertyUpdate(data)
                break
            default:
                console.error('invalid message received:', message.data)
                break
        }
    }

    this.execCallbacks = {}
    this.execId = 0
    this.exec = function(data, callback) {
        if (!callback) {
            // if no callback is given, send directly
            channel.send(data)
            return
        }
        if (channel.execId === Number.MAX_VALUE) {
            // wrap
            channel.execId = Number.MIN_VALUE
        }
        if (data.hasOwnProperty('id')) {
            console.error('Cannot exec message with property id: ' + JSON.stringify(data))
            return
        }
        data.id = channel.execId++
        channel.execCallbacks[data.id] = callback
        channel.send(data)
    }

    this.objects = {}

    this.handleSignal = function(message) {
        var object = channel.objects[message.object]
        if (object) {
            object.signalEmitted(message.signal, message.args)
        } else {
            console.warn('Unhandled signal: ' + message.object + '::' + message.signal)
        }
    }

    this.handleResponse = function(message) {
        if (!message.hasOwnProperty('id')) {
            console.error('Invalid response message received: ', JSON.stringify(message))
            return
        }
        channel.execCallbacks[message.id](message.data)
        delete channel.execCallbacks[message.id]
    }

    this.handlePropertyUpdate = function(message) {
        for (var i in message.data) {
            var data = message.data[i]
            var object = channel.objects[data.object]
            if (object) {
                object.propertyUpdate(data.signals, data.properties)
            } else {
                console.warn('Unhandled property update: ' + data.object + '::' + data.signal)
            }
        }
        channel.exec({ type: QWebChannelMessageTypes.idle })
    }

    this.debug = function(message) {
        channel.send({ type: QWebChannelMessageTypes.debug, data: message })
    }

    channel.exec({ type: QWebChannelMessageTypes.init }, function(data) {
        for (var objectName in data) {
            var object = new QObject(objectName, data[objectName], channel)
        }
        // now unwrap properties, which might reference other registered objects
        for (var objectName in channel.objects) {
            channel.objects[objectName].unwrapProperties()
        }
        if (initCallback) {
            initCallback(channel)
        }
        channel.exec({ type: QWebChannelMessageTypes.idle })
    })
}

function QObject(name, data, webChannel) {
    this.__id__ = name
    webChannel.objects[name] = this

    // List of callbacks that get invoked upon signal emission
    this.__objectSignals__ = {}

    // Cache of all properties, updated when a notify signal is emitted
    this.__propertyCache__ = {}

    var object = this

    // ----------------------------------------------------------------------

    this.unwrapQObject = function(response) {
        if (response instanceof Array) {
            // support list of objects
            var ret = new Array(response.length)
            for (var i = 0; i < response.length; ++i) {
                ret[i] = object.unwrapQObject(response[i])
            }
            return ret
        }
        if (!response || !response['__QObject*__'] || response.id === undefined) {
            return response
        }

        var objectId = response.id
        if (webChannel.objects[objectId]) return webChannel.objects[objectId]

        if (!response.data) {
            console.error('Cannot unwrap unknown QObject ' + objectId + ' without data.')
            return
        }

        var qObject = new QObject(objectId, response.data, webChannel)
        qObject.destroyed.connect(function() {
            if (webChannel.objects[objectId] === qObject) {
                delete webChannel.objects[objectId]
                // reset the now deleted QObject to an empty {} object
                // just assigning {} though would not have the desired effect, but the
                // below also ensures all external references will see the empty map
                // NOTE: this detour is necessary to workaround QTBUG-40021
                var propertyNames = []
                for (var propertyName in qObject) {
                    propertyNames.push(propertyName)
                }
                for (var idx in propertyNames) {
                    delete qObject[propertyNames[idx]]
                }
            }
        })
        // here we are already initialized, and thus must directly unwrap the properties
        qObject.unwrapProperties()
        return qObject
    }

    this.unwrapProperties = function() {
        for (var propertyIdx in object.__propertyCache__) {
            object.__propertyCache__[propertyIdx] = object.unwrapQObject(object.__propertyCache__[propertyIdx])
        }
    }

    function addSignal(signalData, isPropertyNotifySignal) {
        var signalName = signalData[0]
        var signalIndex = signalData[1]
        object[signalName] = {
            connect: function(callback) {
                if (typeof callback !== 'function') {
                    console.error('Bad callback given to connect to signal ' + signalName)
                    return
                }

                object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || []
                object.__objectSignals__[signalIndex].push(callback)

                if (!isPropertyNotifySignal && signalName !== 'destroyed') {
                    // only required for "pure" signals, handled separately for properties in propertyUpdate
                    // also note that we always get notified about the destroyed signal
                    webChannel.exec({
                        type: QWebChannelMessageTypes.connectToSignal,
                        object: object.__id__,
                        signal: signalIndex
                    })
                }
            },
            disconnect: function(callback) {
                if (typeof callback !== 'function') {
                    console.error('Bad callback given to disconnect from signal ' + signalName)
                    return
                }
                object.__objectSignals__[signalIndex] = object.__objectSignals__[signalIndex] || []
                var idx = object.__objectSignals__[signalIndex].indexOf(callback)
                if (idx === -1) {
                    console.error('Cannot find connection of signal ' + signalName + ' to ' + callback.name)
                    return
                }
                object.__objectSignals__[signalIndex].splice(idx, 1)
                if (!isPropertyNotifySignal && object.__objectSignals__[signalIndex].length === 0) {
                    // only required for "pure" signals, handled separately for properties in propertyUpdate
                    webChannel.exec({
                        type: QWebChannelMessageTypes.disconnectFromSignal,
                        object: object.__id__,
                        signal: signalIndex
                    })
                }
            }
        }
    }

    /**
     * Invokes all callbacks for the given signalname. Also works for property notify callbacks.
     */
    function invokeSignalCallbacks(signalName, signalArgs) {
        var connections = object.__objectSignals__[signalName]
        if (connections) {
            connections.forEach(function(callback) {
                callback.apply(callback, signalArgs)
            })
        }
    }

    this.propertyUpdate = function(signals, propertyMap) {
        // update property cache
        for (var propertyIndex in propertyMap) {
            var propertyValue = propertyMap[propertyIndex]
            object.__propertyCache__[propertyIndex] = propertyValue
        }

        for (var signalName in signals) {
            // Invoke all callbacks, as signalEmitted() does not. This ensures the
            // property cache is updated before the callbacks are invoked.
            invokeSignalCallbacks(signalName, signals[signalName])
        }
    }

    this.signalEmitted = function(signalName, signalArgs) {
        invokeSignalCallbacks(signalName, signalArgs)
    }

    function addMethod(methodData) {
        var methodName = methodData[0]
        var methodIdx = methodData[1]
        object[methodName] = function() {
            var args = []
            var callback
            for (var i = 0; i < arguments.length; ++i) {
                if (typeof arguments[i] === 'function') callback = arguments[i]
                else args.push(arguments[i])
            }

            webChannel.exec(
                {
                    type: QWebChannelMessageTypes.invokeMethod,
                    object: object.__id__,
                    method: methodIdx,
                    args: args
                },
                function(response) {
                    if (response !== undefined) {
                        var result = object.unwrapQObject(response)
                        if (callback) {
                            callback(result)
                        }
                    }
                }
            )
        }
    }

    function bindGetterSetter(propertyInfo) {
        var propertyIndex = propertyInfo[0]
        var propertyName = propertyInfo[1]
        var notifySignalData = propertyInfo[2]
        // initialize property cache with current value
        // NOTE: if this is an object, it is not directly unwrapped as it might
        // reference other QObject that we do not know yet
        object.__propertyCache__[propertyIndex] = propertyInfo[3]

        if (notifySignalData) {
            if (notifySignalData[0] === 1) {
                // signal name is optimized away, reconstruct the actual name
                notifySignalData[0] = propertyName + 'Changed'
            }
            addSignal(notifySignalData, true)
        }

        Object.defineProperty(object, propertyName, {
            configurable: true,
            get: function() {
                var propertyValue = object.__propertyCache__[propertyIndex]
                if (propertyValue === undefined) {
                    // This shouldn't happen
                    console.warn(
                        'Undefined value in property cache for property "' +
                            propertyName +
                            '" in object ' +
                            object.__id__
                    )
                }

                return propertyValue
            },
            set: function(value) {
                if (value === undefined) {
                    console.warn('Property setter for ' + propertyName + ' called with undefined value!')
                    return
                }
                object.__propertyCache__[propertyIndex] = value
                webChannel.exec({
                    type: QWebChannelMessageTypes.setProperty,
                    object: object.__id__,
                    property: propertyIndex,
                    value: value
                })
            }
        })
    }

    // ----------------------------------------------------------------------

    data.methods.forEach(addMethod)

    data.properties.forEach(bindGetterSetter)

    data.signals.forEach(function(signal) {
        addSignal(signal, false)
    })

    for (var name in data.enums) {
        object[name] = data.enums[name]
    }
}

//required for use with nodejs
if (typeof module === 'object') {
    module.exports = {
        QWebChannel: QWebChannel
    }
}
